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Item Predicting horse limb responses to surface variations with a 3D musculoskeletal model : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biomechanics at Massey University, Palmerston North, New Zealand(Massey University, 2020) Bardin, AliénorThoroughbred racehorses are often affected by musculoskeletal injuries, leading to involuntary rest periods, early retirement or death. A number of studies have focused on identifying risk factors. A major focus of research has been track surface properties because it should be possible to modify these so that the risk of musculoskeletal injury is minimised. Among all the track surface properties studied to date, consistency of the surface is reported to be one of the main injury risk factors. The aim of this study was to develop a preliminary 3D musculoskeletal model of the whole equine forelimb based on data published in the literature and derived from anatomical measurements; and to determine the effects of the perturbations by the ground surface on the limb response with the musculoskeletal model developed and to assess whether the response occurs acutely in the perturbed stance phase or in the next stance phase. To answer these questions, gait data were collected from ridden Thoroughbreds passing through a perturbation area, where the surface hardness was changed by adding wood or foam under the baseline sand surface. The horses changed their joint flexion/extension patterns in response to changes in hardness. In response to the hard perturbation, the proximal limb spring was more compliant, evidenced by increased shoulder flexion. The elbow and carpal joints were more flexed in the intervening swing phase. In response to the soft perturbation, more coffin joint flexion was observed during both the perturbed and the following stance phase. The preliminary musculoskeletal model of the equine forelimb developed in this thesis allow the observation and study of the forelimb reaction to hardness perturbation through the joint excursions and tendon and ligament strains.Item The effects of partial stable confinement on the voluntary activity of weanling thoroughbred foals : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science, Massey University, Palmerston North, New Zealand(Massey University, 2017) Lilly, Vanessa MareeThis thesis discusses an observational study, which evaluates the effects of partial stable confinement on the voluntary activity of weanling Thoroughbreds kept at pasture. Despite the current knowledge identifying the need for early exercise and pasture access in young Thoroughbreds, there is little information on pasture activity, and none on the effects of partial stable confinement on the amount of, and type of, activity when at pasture. It has previously been stated that young horses confined to a stable at night, spend more time cantering and trotting in the paddock during the day, when compared to their unconfined counterparts- the authors suggested this may be compensation for the lack of activity carried out whilst in confinement. Unfortunately, no further research has been carried out to support this theory, and it is therefore unknown how much confinement is required before horses will carry out compensatory activity, and how length of confinement and the subsequent volume of compensatory activity may affect total average daily activity. A study was carried out on a small commercial Thoroughbred stud farm in the Manawatu, to determine the effects of partial stable confinement on the amount, and type of activity six weanling Thoroughbreds carried out on a daily basis. The horse’s remained under normal management conditions, and were kept at pasture, and confined in loose boxes for an average of three hours a day, on mornings decided by the Stud Master, for handling and yearling sales preparation. Activity was monitored for 141 days using a Heyrex biosensor. The sensor containing a tri-axial accelerometer was attached to each horse’s halter, and the data were recorded as Delta-G; the change in acceleration between respective samples. The data were recorded in 15 minute increments, resulting in approximately 576 records per day and possible 13,536 data points per horse (there was a range of 3,456 - 10,272 usable data points per horse). A total of 39,372 15-minute data points were used in the data analysis. Each horse’s activity profile, including total daily activity, average daily activity and proportion of highand low-energy activity, when at pasture and during confinement was analysed. Total average daily activity varied between horses (70,385 – 95,331, P<0.001), however each horse’s total daily activity was highly repeatable across days with no significant difference between horses between days. Partial confinement resulted in a reduction in average daily activity in all horses (67,682 – 84,737, P<0.0088), except Colt 3 who was more active during days of confinement, than on days of no confinement (89903±5073 and 84813±2163, respectively). Partial stable confinement had no significant effect on the proportion of total activity which was highenergy activity (8.69% on days of confinement, vs 12.23% on days of no confinement) except for Colt 3, who carried out a high proportion of high-energy activity during a day of confinement, then on a day of no confinement (18.23% vs 9.14% respectively). This may be a form of compensation, however it was only noted in one horse, and therefore is more likely to be a behavioural response to being isolated to a stable. The proportion of high-energy activity between the hours of 9am-12pm, when confinement would occur, was also not effected by confinement when compared to days of no confinement (8.64% vs 9.80%, respectively), except in Colt 2, who carried out no high-energy activity whilst in confinement between 9am-12pm. The partial confinement of these weanlings appeared to reduce their overall average daily activity, however it did not affect the amount of high-energy activity. Thus partial confinement may not restrict the all-important osteo-inductive high speed activity required to promote optimal musculoskeletal development in weanlings. However, we lacked the experimental design to examine if there was any association of length of confinement and any compensatory activity. Further studies should examine if the length of partial confinement alters the subsequent activity at pasture.Item Digestibility of Fiberezy® and Timothy Haylage and behavioural observations and voluntary feed intake of FiberEzy® and rye clover hay in Thoroughbred horses : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science, Massey University, Palmerston North, New Zealand(Massey University, 2014) Patel, DeepaThis thesis describes a field study, a laboratory study and two animal studies evaluating the production of timothy grass grown under New Zealand conditions, the composition of a commercially prepared ensiled lucerne and timothy mix ( FiberEzy®: a 50:50 timothy lucerne mix) and ensiled timothy grass;, the stability of FiberEzy® during 12 months of storage; and also the digestibility and voluntary feed intake of FiberEzy®, ensiled timothy grass and Rye-clover hay when fed to Thoroughbred horses. For the field study, grass samples were collected from a representative section (6m x 16m) of a field in Reporoa, (Waikato, New Zealand) sown with timothy grass (Phleum pratense L.) on the 10th of March 2010 at Longitude 176°34’E, Latitude 38°39’S. The samples were collected at regular intervals to investigate changes in the dry matter (DM), acid detergent fibre (ADF), neutral detergent fibre (NDF) and lignin content of the crop over the growing season. There was an increase (17.7to 35.89%) in the dry matter content and lignin content (3.0to 6.3%) of timothy grass over time as the grass matured. Once harvested and ensiled, a sample of timothy grass and FiberEzy® were analysed for total DM, percentages of: crude protein; crude fat; crude fibre; ash; gross energy; hot water soluble carbohydrates; pectin, (NDF), (ADF), lignin, and vitamin E content. Lab analysis showed that FiberEzy® had higher levels of crude protein, pectin, lignin, ash and vitamin E (p<0.05), and lower levels of crude fibre and NDF (P<0.05) than the timothy grass. A shelf life stability study of FiberEzy® (was carried out by sub-sampling a stored bag of the product every 3 months and analysing for total DM, percentage crude protein, percentage hot water soluble carbohydrates and vitamin E (mg/kg) for a total of 12 months. During the storage trial, analysis of FiberEzy® showed an increase in the content of vitamin E (37.6to 124.9mg/kg) over time. A digestibility study was conducted to compare FiberEzy® and New Zealand grown and ensiled timothy haylage on Thoroughbred horses. FiberEzy® and timothy haylage was offered on a DM basis at 2.5% of the body weight to four Thoroughbred horses (10 ± 1 yr; 562.5± 30.7 kg initial BW). The horses were stalled individually in loose boxes (4 x 4 4 m) lined with rubber matting. Horses were randomly paired and assigned to be fed FiberEzy® or timothy haylage for two 18 day periods, in a 2 x 2 Latin square experimental design. Each 18 day period comprised of a 14 day dietary adaptation period where the horses were habituated to the pens and diet, and a 4 day (96 h) total faecal collection. The apparent digestibility of DM and GE were measured on days 15-18; at 12 hourly intervals faecal material from each horse was collected, weighed, and a subsample was taken and frozen at -20°C. One kg samples of the feed were collected and frozen at -20°C on day 15. The energy content of the FiberEzy® and timothy haylage varied between the first and second part of the study, with the DE of timothy haylage varying from 6.9 MJ/kg DM to 9.4 MJ/kg DM. Total energy intake of FiberEzy® and timothy haylage varied between horses, and between groups, with horses fed timothy haylage after FiberEzy® reducing their total energy intake. The apparent digestibility of FiberEzy® tended to be greater than that of timothy haylage. The apparent DM, crude protein and energy digestibility of the feed was similar to values reported in other studies using young horses. A voluntary feed intake (VFI) trial was conducted using six thoroughbred geldings, (10 ± 1 yr; 550.6±15.8 kg) were offered FiberEzy® or Rye-clover hay at >3% of the body weight. The horses were again stalled individually in loose boxes (4 x 4 m) lined with rubber matting. Voluntary feed intake was measured over 17 days. Day 1 to 8 was the adaptation phase and from day 9-17 of the study the horses were scan sampled and videoed for two hours every morning(9:30-11:30 am) after feeding and two hours in the evening (4:30-6:30 pm) after feeding. There were significant differences in VFI between time periods (24.3±0.9 vs 17.8±0.4 kg DM /day, p<0.05) and between feeds (FiberEzy®: 24.3±0.4 vs. Rye-clover hay: 17.8±0.7 kg DM /day) but not an interaction. Behaviours were typical of loose box housed horses and differences in feeding behaviour observed correlated with the differences in VFI measured between feeds. The results of this thesis suggest that FiberEzy® is a suitable alternative to concentrate-based supplementary feed.Item Flexural limb deformities in thoroughbred foals in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree Master of AgriScience (Equine) at Massey University, Manawatu, New Zealand(Massey University, 2014) Shotton, Amanda KylieThe aims of this thesis were to describe the descriptive epidemiology of congenital flexural limb deformities (FLD) in foals on commercial Thoroughbred stud farms, and to describe the management and treatment of these foals. Data were collected on five commercial Thoroughbred stud farms in the Auckland and Waikato regions. Data were collected primarily by stud farm personnel, and assisted by study personnel when on farm. Data were collected on a selective population of 203 foals during the 2013/2014 season. Pre-selection by stud farm personnel towards foals with FLD prevented the calculation of prevalence and resulted in 67% (135/203) of the foals with records having one or more FLD recorded. Laxity was observed to affect 87/135 foals, contracture of at least one joint region 57/135 foals and 6/135 foals were back at the knee; nine foals suffered from multiple forms of deformity. The median score for laxity was 2 (IQR 2-3) on a four point scale. The median score for contracture affecting hoof-ground contact was 2 (IQR 2-3) on a three point scale, while the median score for contracture affecting the fetlock and carpal regions was 2 (IQR 2-2). Multiple scorings over time were provided for 69/135 foals, 64 of these foals showed improvement in the severity of deformities by the final scoring. Inter-observer agreement (between study personnel) was strong when scoring flexural laxity (k=0.95), contracture affecting hoof-ground contact (k=1.00) and contracture in the joint regions (k=0.85). In contrast, inter-observer agreement between study personnel and stud farm personnel was lower when scoring flexural laxity (k=0.69) and when scoring contracture in the fetlock and carpal regions (k=0.14). Treatment data were provided for 40/135 foals. Confinement was the most common form of treatment provided for mild and moderate cases of flexural contracture and flexural laxity; severe cases of flexural contracture required more invasive forms of treatment in combination with confinement. Improvement in the severity of deformities was observed following treatment in 28/42 (67%) cases of contracture observed to effect hoof-ground contact, 33/43 (77%) cases of contracture affecting the fetlock and carpal regions and 36/56 (64%) cases of laxity. This thesis provides insight into the effect of FLD on Thoroughbred foals in New Zealand. The results indicate that foals tend to be mildly or moderately affected by FLD at birth and that treatment by stud farms is pragmatic.Item Growth, voluntary feed intake and digestibility in thoroughbred weanlings : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science, Massey University, Palmerston North, New Zealand(Massey University, 2013) Bishop, Lana MicheleThis thesis describes two studies evaluating the suitability of an ensiled lucerne and cracked maize feed for consumption by Thoroughbred weanling horses (eight to twelve months of age). A growth study was conducted to compare the effect of a fibre-based (ensiled lucerne and cracked maize) or concentrate-based supplementary feed (commercial weanling concentrate) on the growth and occurrence of gastric ulceration of Thoroughbred weanling fillies managed under commercial conditions in New Zealand at moderate followed by high feeding levels. During the trial there was an outbreak of strangles (Streptococcus equi var. equi) in both groups of horses. Three of the fibre-supplemented and two of the concentrate-supplemented weanlings displayed clinical signs of strangles during the moderate and high supplementary feeding periods, respectively. These weanlings were isolated from their groups for the duration that they displayed clinical signs of strangles. During the growth trial the weekly body weight gain, wither height and average daily gain (ADG) were not affected by dietary treatment or feeding level. Weekly body weight gain, body condition score and ADG were significantly lower in the weanlings that were infected with S. equi var. equi while they were isolated in comparison to the remainder of their group. No association was found between gastric ulceration and dietary treatment. At the completion of the growth study, a separate voluntary feed intake (VFI) and apparent digestibility study of the ensiled lucerne and cracked maize feed was conducted over a 21 day period using six of the Thoroughbred weanling horses. During this study the duration of total faecal collection required for consistent apparent digestibility measures of dry matter, crude protein and gross energy was determined. The VFI of the ensiled lucerne and cracked maize feed by the weanling horses (94.57 ±1.43 g DM/kg BW0.75) was at the lower end of the range reported by other studies of VFI in young horses fed grass or lucerne hay alone, or in combination with concentrate rations (92.3-134 g DM/kg BW0.75). The feed contained 53.96% (±0.72) DM, and 13.22% (±0.10), CP and 12.47 MJ/kg DM (±0.01) GE on a DM basis. The apparent dry matter (70.55 ±0.40%), crude protein (62.39 ±0.60%) and gross energy (68.51 ±0.43%) digestibility of the feed was similar to other studies of young horses fed lucerne hay and lucerne hay and concentrate diets. There was no significant difference in the duration of total faecal collection on all of the apparent digestibility measures. The results of this thesis suggest that the ensiled lucerne and cracked maize feed is a suitable alternative to concentrate-based supplementary feeds that are typically fed to grazing weanlings, and that normal growth rates can be achieved by weanlings supplemented with this feed. Additionally, the apparent dry matter, crude protein and gross energy digestibilities of this feed can be accurately measured over a 12 hour total faecal collection.Item Birth weight and growth of New Zealand thoroughbred foals : a thesis presented impartial [i.e. in partial] fulfilment of the requirements for the degree of Master of Veterinary Studies at Massey University, Palmerston North, New Zealand(Massey University, 2008) De Freitas Aiex, LucianaThe success of the New Zealand Thoroughbred horse industry is highly dependant on the production of good foals. The birth weight of the foal, and its weaning weight, is closely associated with maternal factors, such as age, parity, size, and nutrition. Age is associated with endometrosis and limited placentation, which leads to a reduction in foal birth weight. Multiparous mares tend to produce larger foals than primiparous mares because of the priming effect that a first pregnancy has on the uterus. Nutrition affects the size of the mare, which is positively correlated with foal birth weight. The size of the mare is positively correlated with birth size of the foal, and the birth weight of the foal is positively correlated with the mass, gross area and volume of the allantochorion. and the total area of foetomaternal contact. The information available on the maternal effects on foal birth weight is limited. This study attempts to improve our understanding of this relationship by examining data collected from New Zealand Thoroughbred mares, which are held on pasture throughout the year and may receive little supplementary feed during pregnancy. Data were collected from 49 New Zealand Thoroughbred marcs and their foals during the 2004 foaling season. Analyses were conducted to determine whether the age, parity, body condition score, weight pre- and post-partum, and height of the mare, the length of gestation and the allantochorion weight and volume were associated with foal sex ratio (n = 49), foal wet birth weight (n = 27), day 1 weight (n = 49), and foal height (n = 49). The daily growth of a subgroup of 15 foals in their first two weeks of life was monitored. In addition, age and parity data was collected via the online Thoroughbred Studbook from 492 mares that were bred to one of the Waikato Stud stallions in the 2001 breeding season. The mean age of mares was 10.8 ± 0.8 years for the Newmarket Lodge population and 11.0 ± 0.2 years for the Waikato Stud population; the mean parity of mares was 4.5 ± 0.4 for the Newmarket Lodge population and 5.9 ± 0.2 years for the Waikato Stud population; and the mean length of gestation was 355.67 ± 1.26 days. The age and parity of the mare and the sex of the foetus had no significant effect on the length of gestation. Primiparous mares had significantly lighter and lower foals than multiparous mares, independently of the age of the mare. The mean wet birth weight of foals was 54.6 ± 1.1 kg and the mean day 1 weight was 55.7 ± 0.8 kg. The range of foal birth weights was from 41.0 to 66.5 kg. The sex of the foal did not significantly affect its wet birth weight and day 1 weight. The mean wet birth weight was 54.1 ± 2.1 for a filly, and 55.0 ± 1.3 for a colt. The mean day 1 weight was 55.2 ± 1.4 for a filly and 56.2 ± 1.1 for a colt. The relationship between the wet weight of the foal and its day 1 weight was highly significant. Mare age and parity affected the weight and volume of the allantochorion. The allantochorions of primiparous and multiparous mares aged 16 years and over were lighter and had lower volumes than those of multiparous mares aged five to 15 years. There was no difference in the weight and volume of the allantochorions of primiparous mares and multiparous mares aged 16 years and over. The mean weight of the allantochorion was 3.68 ± 0.09 kg. and the mean volume was 2.86 ± 0.07 litres. The weight and volume of the allantochorion were significantly associated with the wet birth weight and day 1 weight of the foal. Moreover, the weight of the mare pre- and post-partum significantly affected the wet birth weight, the day 1 weight, and the height of the foal. Mares lost an average of 80.9 kg liveweight with the foaling process. Foals lost on average 1.17 ± 0.94 kg between the wet birth weight and day 1 weight measurements. Seventy percent of foals lost weight between these measurements. The average daily weight gain of foals from day 2 to day 14 of life was 1.71 ± 0.11 kg. The average weight gain of foals was 25.05 ± 1.02 kg in the first 14 days of life. The mean height of foals at birth was 1.028 ± 0.008 m and they grew on average 0.062 ± 0.005 m to reach a mean height of 1.087 ± 0.005 m at two weeks of age. The average daily height increase from day 1 to day 14 was 0.004 ± 0.002 m. There was no significant influence of the sex of the foal on the weight gain and height increase from day 1 to day 14. although the mean wet birth weight, day 1 weight and day 14 weight of colts is slightly higher than that of fillies. Maternal factors influence the birth size of the NZTB foal born to mares kept on pasture. The weight of the mare is closely associated with the size of the allantochorion. which is significantly associated with the birth weight of the foal. Primiparous and older mares (≥ 16 years) produce smaller foals than multiparous mares younger than 16 years. Foals lose weight in the first 24 hours after birth. This early neonatal weight loss probably occurs because of drying off. The sex of the foal did not affect the length of gestation, and it did not influence the birth weight of the foal and its daily growth in the first two weeks post-partum. The information in this study has not been previously reported for horses in New Zealand.